<!DOCTYPE html>
<html lang="zh-CN">

<head>
  <meta charset="UTF-8">
  <title>demo</title>
  <link rel="stylesheet" href="./style.css">
</head>

<body>

  <div class="container">
    <div class="input-group">
      <input type="text" id="input1" placeholder="1 * (2 + 3) / 4 = 0">
      <div id="code">未输入内容</div>
    </div>
  </div>

</body>
<script src="./css_more_fix.js"></script>

</html>